As temperatures near triple digits, Atlas Tracy, 3, of Gilbert, tries to pull his aunt, Nikki Tracy of Phoenix, into the water at the splash pad at Riverview Park in Mesa on Oct. 24, 2017. David Wallace/azcentral sports

Light strikes over the the Tanque Verde wash, partially filled with standing water from runoff on Tanque Verde Loop Rd., from the tail end of a monsoon storm, Friday, July 28, 2017 in Tucson, Arizona. Kelly Presnell/Special to The Republic

A driver who drove passed a “road closed” sign on Citrus Road, just south of Interstate 10 in Goodyear, got stuck in the mud July 24, 2017, after thunderstorms moved through the Valley. Tom Tingle/The Republic

Extensive damage was done to the Desert Canyon Golf Course clubhouse in Fountain Hills during an intense storm Sunday night, July 16, 2017. The roof sustained much of the damage which allowed water to enter the building, destroying carpet and furniture. Tom Tingle/The Republic

Victor Blackwell and his son Dax, 16, help clear a fallen tree outside a home in Gold Canyon, Arizona, on July 11, 2017. The tree was blown over during monsoon storms the previous evening. Loren Townsley/ The Republic

The last of the day's sunlight pokes through a monsoon storm building up over the northwest area of the valley, generating lightning strikes but little precipitation, Saturday, July 8, 2017 in Tucson. Kelly Presnell/Arizona Daily Star

A bolt cuts through the clouds over the northwest part of town, one of numerous lightning strikes from monsoon storm cells blowing up around the city but leaving no rain, Saturday, July 8, 2017 in Tucson. Kelly Presnell/Arizona Daily Star

A lightning bolt strikes in the western Santa Catalina foothills from storm clouds north of downtown and the buildings of the University of Arizona, Thursday, July 6, 2017 in Tucson. Kelly Presnell/Arizona Daily Star

McDade estimated that a punctured line from the rooftop was releasing up to 50 gallons of water per minute into the library. Video shot by Phoenix fire officials showed water pouring onto shelves of books.

McDade said crews tried to prevent as much water damage as possible.

"We understand what's housed in here," McDade said. "We've got books, we've got artifacts and we've got the history of the city here so while we were trying to mitigate the water flow we were working on trying to salvage the damage that was happening all at once."

McDade said roof tiles also appear to have lifted up and settled back onto the roof several times during the storm, describing it as "like the wave of an ocean."

Crews used vacuums, suction equipment and squeegees to funnel the water out of the library floors.

Heavily-damaged areas included the MACH (Makers, Artists, Crafters, Hackers) Center, a part of the library devoted to hobbies such as video game design, science, and 3D printing located on the fourth floor.

The fifth floor, closest to the water source, housed non-ficition and reference books.